Continuous dowel bar support



March 5, 1957 D, M DE CAMO 2,783,695

CNTINUOUS DOWEL BAR SUPPORT Filed May 4,1953

........... INVENTOR.

United States Patent() "Ice e CONTINUOUS DOWEL BAR SUPPORT Dominick M. De Canio, Chicago, Ill., assignor to Universal Form Clamp Co., Chicago, Ill., a corporation of Illinois Application May 4, 1953, Serial No. 352,719

1 Claim. (Cl. 948) This invention relates to the art of concrete pavement expansion joints wherein adjacent edges of the pavement have embedded therein dowels providing a continuous reinforcement for the concrete sections and permitting relative movement therebetween in response to temperature changes. More particularly the invention is directed to a continuous dowel bar support for such expansion joints.

Where dowel bars are used for load transfer across transverse joints in concrete pavements, it is essential that they be located accurately if they are to serve the intended purpose. Necessanly, the dowel bars must'be parallel to the axis of the pavement in order that the expansion and contraction of the pavement be along the axis of the dowels. Further, it has been found necessary to use transverse bar spacers and supports for positive assurance of the accurate alignment of the dowels. Experience has indicated that the best way of achieving this accurate alignment of the dowels is to use a continuous spacer and support for the dowel bar assemblies.

The primary object of the present invention is to provide an improved form of continuous dowel bar support which positively xes the individual dowel bar supports or chairs relative to each other, and wherein the two rows of chairs are maintained parallel and at fixed distances from each other and from the pavement joint. Another object of the invention is to provide an improved continuous dowel bar support including means for interlocking the dowel bar and spacer bar in position on the support to prevent any relative displacement thereof during the positioning of the expansion joint or the pouring ofthe concrete.

Other objects and advantages of the invention will become apparent as the disclosure progresses with respect to the accompanying drawings, wherein:

Figure 1 is a side elevation of a portion of the continuous dowel bar support; a dowel bar and a supporting cross bar being indicated by broken lines.

Figure 2"` is an end view of the structure shown in Figure l.

Figure 3 is a fragmentary perspective view of the joint packing and reinforcing assembly employing the continuous dowel bar support shown in Figures l and 2.

Figure 4 is a reduced, top plan view of the complete expansion joint assembly, the concrete pavement being indicated by dotted lines.

Referring to the drawing, it is seen that the present invention is directed to an improved form of continuous dowel bar support for a pavement expansion joint, which comprises two parallel rows of chairs 5 interconnected by a series of cross rods v6 and providing a support for dowel bars 7 extending transversely of the joint 8, and a pair of cross bars or spacers 9 disposed on opposite sides of the expansion joint. The dowel and cross bar supporting structure is formed as a unitary structure, with a selected spacing between the rows of chairs and with the length of the rows conforming with the width of the 2,783,695 rammed Mar. 5, 1957 downwardly extending, parallel legs 10, and a laterally offset V-shaped support 11 for the dowel bar 7 which is positioned intermediate the upper ends of the legs 10. The laterally offset support 11 is continuous with the upper ends of the legs and includes a pair of U-shaped seats 12 formed by the laterally bent upper-end portions of the legs for receiving the cross bar 9 extending between adjacent chairs of each row and-forming a direct support for the dowel bar 7. The bar 9 preferably rests on the seats 12 without being welded to the chairs.

The adjoiningl chairs of each row are xedly interconnected by an upper tie rod 13 and a lower tie rod 14 so as to position the legs 10 of the several chairs in a common plane and, also, to align the seats 12 for the c ross bar 9. Preferably the lower tie rod 14 is disposed above the lower end of the legs 1t? so that the latter present projecting end portions for insertion into the dirt bed on which the pavement is laid. The upper tie rods are placed at a suitable distance above the seats 12 to accommodate the transversely arranged dowel 7 and cross bar 9 in closely fitting relation to their-seats and the upper tie rod. The tie rods 13 and 14 are preferably spot welded to the chairs 5.

As shownin Figure 3, the parallel rows of chairs are xed in a predetermined laterally spaced relation by a number of cross rods 6, which are welded, or otherwise fastened, to the chair legs 10 or to the lower tie rods 14 in transversely extending relation thereto. If desired, the cross rods 6 may be bent at their mid-portion to provide a downwardly extending U-shaped offset portion for receiving the lower edge portion of the packing slab 17, as shown in the Lord Patent No. 2,133,553. The two cross bars 9 are positioned in each of the aligned series of seats 12 formed by the chairs, and each of the transversely disposed dowel bars 7 are arranged in their end supports 11 in snugly fitting relation between the underlying cross bars 9 and the overlying tie rods 13. The intermediate portion of each of the dowel bars extends through an opening in the packing slab 17 and the usual dowel bar socket 19, known in the trade as a whistle, is positioned on one end of the dowel bar. Figure 4 illustrates a typical expansion joint utilizing the continuous support or basket just described with the adjoining pavement slabs being shown in part and indicated by the letters S and S. Y

By virtue of the described construction, there is provided an improved form of basket or continuous dowel bar support which may be fabricated in advance of the need therefor, and which adapts itself readily to the complete assembly of the expansion joint along the side of lthe road bed for movement as a unit into position on the road bed. Of course, it is understood that the continuous dowel bar support may be constructed with chairs of various height as well as different spacings thereof in order to accommodate the requirements of individual jobs.

The tie rods 13 and 14 and the cross rod 6 serve to maintain the individual chairs 5 in xed position with respect to one another and, also, to insure accurate disposition of the two rows of dowel and spacer bar supports in parallel relation to each other and to the expansion joint packing slab 17. This arrangement of parts also provides a rigid structure for the afore-mentioned oitthe-road assembly, as well as insuring stability of the expansion joint during the pouring of the concrete.

The particular disposition of the dowel bar support 11,

3. the cross bar seats 12, and the upper tie rod 13 at each of the chairs 5 is of great importance in'mainta-ining the dowel bars 7 and the cross bars 9 in fixed position during the pouring of the concrete over the expansion joint assembly. Thus, there is avoidedA anysliiftingfo'ftliepacking slab 17 during the pouring operation. The'novel arrangement of the aforementioned-elements ofthe' chair S is such that the cross bar 9 and dow'el bar 7 can be readily slipped into place, and still prevent lateral and vertical movement ofthe dowel bar when the basketassernbiy is complete. Y

While described with respect to a particular embodiment, it will be understood that various modifications thereof might be made without departing from the principles of the present invention.

I claim:

In a continuous spacer andfsup'port for dowel bar assemblies for supporting a-iiller strip, a plurality of spaced parallel dowel bars, a pair of 'spaced apart continuous dowel bar supports, anda pair of cross bars supported on said dowel bar supports, each of said continuous dowel bar supports comprising a row of spaced apart chairs, each of said chairs comprising asingle length of wire bent intermediate its ends to form a pair of substantiaily parallel legs having their lower end portions dis posed in a continuous common plane, the upper portion of each leg being bent laterally of the plane of saidlegs in an opposite direction from the other dowel bar support to provide a U-shaped portion with the bight of said U-shaped portions providing a pair of aligned seats for one of said cross bars which is disposed generally parallel to theeplanebf sad'legs, said U-shaped portionslaving their outermost leg portions, with respect to said cross bar seat, extending upwardly higher than their inner leg portions and joined by a downwardly bent generally V-shaped seat for supporting an end of one of said dowel bars, said V-shaped seat section being disposed transversely of the position of the cross bar seats and above the latter, said V-shaped seat section having the inner bottom bent portion thereof located approximately at the upper level of said cross bar thereadjacent, a first tie rod interconnecting the outermost leg portions of each of said U-shaped portions of the rows of chairs at a position above said dowel bar and cross bar seats, a second tie rod interconnecting the lower end portions of the legs of each of said rows of chairs, and a plurality of additional rods interconnecting said parallel rows of chairs adjacent the lower end portions of the vertical legs thereof and at spaced intervals' therealong.

References Cited in the tile'of this patent UNITED STATES PATENTS 1,114,147 Kerr oct. 2o, 1914 1,119,123 Schoenthaler Dec. 1, 1914 1,908,105 Bitney May 9, 1933 2,133,553 Lord soct. 18, 193s 2,439,428 Hillberg Apr. 13, 1948 2,531,552 Brickman Nov. 28, 1950 2,627,793 White' Feb. l0, 1953 2,642,789 Brickman June 23, 1953 

